Ever since man first began exploring the cosmos and traveling to the Moon, we’ve been searching for evidence of whether or not alien life exists in the universe.
But how can we prove the existence of extraterrestrial life beyond the Earth?
According to Harvard astronomy professor Abraham Loeb, the first place we need to look for life is on the surface of the Moon.
In a fascinating op-ed he wrote for Scientific American, Professor Loeb speculates that our Moon may contain proof of what came long before mankind appeared on Earth:
“Can the moon provide clues for extraterrestrial life? A new paper I wrote with Manasvi Lingamanswers this question in the affirmative. The idea is to consider the moon’s surface as a fishing net for interstellar objects collected over time and potentially deliver building blocks of life from the habitable environments around other stars.”
The Lunar Mailbox
Loeb goes on to argue that anything which may have collided with the Moon would have left traces. That includes, he notes, alien life forms or advanced technology that extraterrestrials might have used for their own lunar exploration and then left behind:
“The lack of a lunar atmosphere guarantees that these messengers would reach the lunar surface without burning up. In addition, the geological inactivity of the moon implies that the record deposited on its surface will be preserved and not mixed with the deep lunar interior. Serving as a natural mailbox, the lunar surface collected allimpacting objects during the past few billions of years. Most of this ‘mail’ comes from within the solar system.
“But the solar system also intercepts objects from interstellar space, ranging from dust particles to free-floating planets and stars.”
Hiding in Plain Sight?
While skeptics may try to suggest that Moon rocks and other debris brought back by NASA missions to the Moon would have already yielded evidence of alien life from the surface of the Moon, Loeb counters such arguments by reminding readers that the Moon rocks returned to Earth were likely contaminated by human hands and are therefore not a good indicator of what might actually exist or once existed there:
“Identifying biomarkers from debris of material that originated in the habitable zone around other stars would inform us about the nature of extraterrestrial life. The fundamental question is whether distant life resembles the biochemical structures we find on Earth. Similarities might imply that there exists a unique chemical path for life everywhere or that life was transferred between systems. Either way, a lunar study shortcuts the need to send spacecraft on extremely long missions to visit other star systems.”
Once we have samples to examine — perhaps at a lab located directly on the Moon? — we can then begin to find markers which will tell us what came eons ago, Loeb speculates:
“How can extrasolar origin be identified? The simplest flag would be a deviation from the unique solar ratio for isotopes of oxygen, carbon or nitrogen. Laboratories have already demonstrated the feasibility of this method at the required sensitivity levels.”
Loeb ends his essay by reminding us that man has always been willing to explore and find new horizons. Now we have a chance to answer one of the questions that have long confounded us:
“The opportunity to discover signs of extraterrestrial life provides a new scientific incentive for a sustainable base on the lunar surface. The moon is well known for its romantic appeal, but astrobiology offers a twist on this notion. Here’s hoping that the moon will inform our civilization that we are not alone and that someone else is waiting for us out there.”
What do we have to lose by trying?
Here’s more on how we can use the Moon as a “fishing net” for evidence of alien life in the universe:
Featured Image Brendan Keene/Flickr